1. Field of the Invention
The invention relates to a side panel assembly and, more particularly, to a side panel assembly for a flat bed semi-trailer.
2. Summary of Related Art
Various methods for the construction of semi-trailer side walls have been used. Typically, the side walls are formed of continuous sheets of aluminum and are stiffened by internal or external vertical side posts. Unitary plywood panels, coated on either face with fiberglass-reinforced polyester, have also been used to form the side walls of cargo-carrying containers and trailer bodies in conjunction with aluminum structural members to which the edges of the plywood panels are secured by bolts.
On the other hand, it is often desired that the side walls be removable and replaceable so that the trailer may be loaded from the sides and then the side walls replaced, or so that the trailer can be run flat for wide loads. Such side walls have heretofore been formed of a plurality of side panels, each consisting of a sheet of plywood which is supported at its bottom edge by the trailer flooring, and at the opposing side edges in channels formed in aluminum framing members mounted vertically about the periphery of the trailer bed. In some instances, these plywood panels have been provided with a coating of fiberglass-reinforced plastic on both sides. However, there are considerable disadvantages with the plywood side panels used previously: they have substantial weight, lack dimensional stability, often quickly become aesthetically objectionable, and require excess maintenance and early replacement due to the natural deterioration of the wood.